package com.wangzh.collection.map;

import java.util.HashMap;
import java.util.Map;
import java.util.TreeMap;

public class Demo {
    public static void main(String[] args) {
        Map<String, Integer> map = new HashMap<>();

        new TreeMap<>();

//        map.put("a", 3);
        System.out.println(map.getOrDefault("a", 1));

        System.out.println(map);
    }
}
